This study utilizes information and specimens from the Collaborative Perinatal Research and several cooperative studies to identify pregnancies complicated by maternal infections or infections in childhood; to further delineate these causes by serologic testing of the stored sera; to determine outcome of these pregnancies in relation to the outcomes of matched controls; and to gain information on the frequency of maternal infections during pregnancy and their effects on the developing fetus. Studies using antigens for EB virus, hepatitis and several Coxsackie B viruses will be initiated.